Imidochromium compounds in catalyst systems for olefin polymerization

ABSTRACT

The present invention relates to catalyst system containing at least one imidochrome compound and at least one activation compound. This invention also relates to imidochrome compounds, to a method for olefin polymerization and to methods for producing said imidochrome compounds.

[0001] The subject matter of the present invention is catalyst systems containing imidochromium compounds, new imidochromium complexes, a process for the polymerization of olefins as well as a process for the production of imidochromium complexes.

[0002] Many of the catalyst employed for the polymerization of α-olefins are based on immobilized chromium oxides (see, for example, Kirk-Othmer, “Encyclopedia of Chemical Technology”, 1981, Volume 16, page 402). Such catalyst generally yield ethylene homopolymers and ethylene copolymers having high molecular weights although they are relatively insensitive to hydrogen, as a result of which they do not allow a simple control of the molecular weight. In contrast, the use of bis(cyclopentadienyl)chromium (U.S. Pat. No. 3,709,853), bis(indenyl)chromium or bis(fluorenyl)chromium (U.S. Pat. No. 4,015,059), which is applied onto an inorganic, oxide support, makes it possible to easily regulate the molecular weight of polyethylene through the addition of hydrogen.

[0003] As is the same case with Ziegler-Natta systems, chemists have recently sought for catalyst systems having a uniformly defined, active center, the so-called single-site catalysts, also for chromium compounds. The systematic variation of the ligand skeleton is supposed to make it easy to change the activity, the copolymerization behavior of the catalyst and the properties of the polymers thus obtained.

[0004] The preparation of bis(tert.-butylimido)bis(trimethylsiloxy)chromium by means of the reaction of dioxochromium dichloride with tert.-butyl(trimethylsilyl)amine was described by W. Nugent et al. in Inorg. Chem. 1980, 19, pages 777 to 779. Diaryl derivatives of this compound, namely, bis(tert.-butylimido)di(aryl)chromium were prepared by G. Wilkinson et al. as presented in J. Chem. Soc. Dalt. Trans. 1988, pages 53 to 60. The corresponding dialkyl complexes were described for the first time by C. Schaverien et al. (Organomet. 9 (1990), pages 774 to 782). They were also able to isolate a monoimidochromium compound tert.-butylimido(oxo)chromium dichloride by reacting tert.-butylimido-bis(trimethylsilanolato)oxochromium with phosphorus pentachloride (W. Nugent in Inorg. Chem. 1983, 22, pages 965 to 969).

[0005] EP-A 0,641,804 describes the use of bis(alkylamido)chromium(VI) and bis(arylimido)-chromium(VI) complexes for the polymerization of olefins. In EP-A 0,816,384, these bis(imido)chromium(VI) complexes are supoposed on polyaminostyrene for the polymerization of ethylene and copolymerization of ethylene with higher α-olefins. In the context, the preparation of bis(arylimido)chromium dichloride is a three-stage synthesis route since the reaction of dioxochromium dichloride with N-trimethyl-silylanilines does not yield bis(arylimido)chromium dichloride.

[0006] G. Wilkinson et al. were able to prepare tert.-butylimidochromium(V)trichloride and its donor-coordinated derivatives (J. Chem. Soc. Dalt. trans. 1991, pages 20051 to 2061).

[0007] The objective of the present invention was to find new catalyst systems that can be easily modified and that are suitable for the polymerization of α-olefins.

[0008] Moreover, the objective was to find an improved synthesis route for the preparation of bis(imido)chromium(VI) compounds.

[0009] Accordingly, catalyst systems have been found, containing:

[0010] (A) at least one imidochromium compound, which can be obtained by a process encompassing the following steps:

[0011] (a) contacting a dioxochromium compound with N-sulfonyl compound R¹-N═S═O or R²-N═S═O, wherein the variables have the following meaning:

[0012] R¹ stands for C₁-C₂₀-alkyl, C₂-C₂₀-alkenyl, C₆-C₂₀-aryl, alkylaryl having 1 to 10 carbon atoms in the alkyl radical and 6 to 20 carbon atoms in the aryl radical, whereby the organic radical R¹ can also have inert substituents, for SiR³ ₃;

[0013] R² stands for R³C═NR⁴, R³C═O, R³C═O(OR⁴), R³C═S, (R³)₂P═O, (OR³)₂P═O, SO₂R³, R³R⁴C═N, NR³R⁴ or BR³R⁴;

[0014] R³, R⁴ independent of each other, stand for C₁-C₂₀-alkyl, C₂-C₂₀-alkenyl, C₆-C₂₀-aryl, alkylaryl having 1 to 10 carbon atoms in the alkyl radical and 6 to 20 carbon atoms in the aryl radical, for hydrogen if the latter is bonded to a carbon atom, whereby the organic radicals R³ and R⁴ can also have inert substituents;

[0015] (b) contacting the reaction product thus obtained with chlorine if a sulfonyl compound R¹-N═S═O was used and, in case an N-sulfinyl compound R²-N═S═O was used, with chlorine or sulfurichloride or with no other reagent;

[0016] (B) at least one activator compound and

[0017] (C) optionally, one or more additional catalyst commonly employed for the polymerization of olefins.

[0018] Furthermore, imidochromium compounds having the general formula II,

[0019] were found, wherein variables have the following meaning:

[0020] R² stands for R³C═NR⁴, R³C═O, R³C═O(OR⁴), R³C═S, (R³)₂P═O, (OR³)₂P═O, SO₂R³, R³R⁴C═N, NR³R⁴ or BR³R⁴;

[0021] X independent of each other, stands for fluorine, chlorine, bromine, iodine, NR⁵R⁶, NP(R⁵)₃, OR⁵, OSi(R⁵)₃, SO₃R⁵, OC(O)R⁵, β-diketonate, sulfate, dicarboxylates, dialcoholates, BF₄ ⁻, PF₆ ⁻, or bulky weakly or non-coordinating anions;

[0022] R³-R⁶ independent of each other, stand for C₁-C₂₀-alkyl, C₂-C₂₀-alkenyl, C₆-C₂₀-aryl, alkylaryl having 1 to 10 carbon atoms in the alkyl radical and 6 to 20 carbon atoms in the aryl radical, for hydrogen if the latter is bonded to a carbon atoms, whereby the organic radicals R³ and R⁴ can also have inert substituents;

[0023] m is 1 for dianionic X, 2 for monoanionic X.

[0024] Imidochromium compounds having the general formula III,

[0025] were likewise found, wherein the variables have the following meaning:

[0026] R² stands for R³C═NR⁴, R³C═O, R³C═O(OR⁴), R³C═S, (R³)₂P═O, (OR³)₂P═O, SO₂R³, R³R⁴C═N, NR³R⁴ or BR³R⁴;

[0027] X independent of each other, stands for flourine, chlorine, bromine, iodine, NR⁵R⁶, NP(R⁵)₃, OR⁵, OSi(R⁵)₃, SO₃R⁵, OC(O)R⁵, β-diketonate, sulfate, dicarboxylates, dialcoholates, BF₄ ⁻, PF₆ ⁻, or bulky weakly or non-coordinating anions;

[0028] R³-R⁶ independent of each other, stand for C₁-C₂₀-alkyl, C₂-C₂₀-alkenyl, C₆-C₂₀-aryl, alkylaryl having 1 to 10 carbon atoms in the alkyl radical and 6 to 20 carbon atoms in the aryl radical, for hydrogen if the latter is bonded to a carbon atoms, whereby the organic radicals R³ and R⁴ can also have inert substituents;

[0029] m is 1 for dianionic X, 2 for monoanionic X;

[0030] L is a neutral donor;

[0031] n is 0 to 3.

[0032] Furthermore, a process was found for the production of an imidochromium compound having the general formula IV,

[0033] wherein the variables have the following meaning:

[0034] R¹ stands for C₁-C₂₀-alkyl, C₂-C₂₀-alkenyl, C₆-C₂₀-aryl, alkylaryl having 1 to 10 carbon atons in the alkyl radical and 6 to 20 carbon atoms in the aryl radical, whereby the organic radical R¹ can also have inert substituents, or SiR³ ₃;

[0035] Z independent of each other, stands for C₁-C₂₀-alkyl, C₂-C₂₀-alkenyl, C₆-C₂₀-aryl, alkylaryl having 1 to 10 carbon atoms in the alkyl radical and 6 to 20 carbon atoms in the aryl radical, for fluorine, chlorine, bromine, iodine, NR⁵R⁶, NP(R⁵)₃, OR⁵, OSi(R⁵)₃, SO₃R⁵, OC(O)R⁵, β-diketonate, sulfate, dicarboxylates, dialcoholates, BF₄ ⁻, PF₆ ³¹ , or bulky weakly or non-coordinating anions;

[0036] R³, R⁵, R⁶ independent of each other, stand for C₁-C₂₀-alkyl, C₂-C₂₀-alkenyl, C₆-C₂₀-aryl, alkylaryl having 1 to 10 carbon atoms in the alkyl radical and 6 to 20 carbon atoms in the aryl radical, for hydrogen if the latter is bonded to a carbon atom, whereby the organic radicals R³, Rphu 5 and R⁶ can also have inert substituents;

[0037] p is 1 for dianionic Z, 2 for monoanionic Z;

[0038] characterized in that a dioxochromium compound is reacted with an N-sulfinyl compound R¹-NSO.

[0039] A process for the production of imidochromium compound having the general formula I,

[0040] was likewise found, wherein

[0041] X independent of each other, stands for fluorine, chlorine, bromine, iodine, NR⁵R⁶, NP(R⁵)₃, OR⁵, OSi(R⁵)₃, SO₃R⁵, OC(O)R⁵, β-diketonate, sulfate, dicarboxylate, dicoholates, BF₄ ⁻, PF₆ ⁻, or bulky weakly or non-coordinating anions;

[0042] R¹ stands for C₁-C₂₀-alkyl, C₂-C₂₀-alkenyl, C₆-C₂₀-aryl, alkylaryl having 1 to 10 carbon atoms in the alkyl radical and 6 to 20 carbon atoms in the aryl radical, whereby the organic radical R¹ can also have inert substituents, or SiR³ ₃;

[0043] R³, R⁵, R⁶ independent of each other, stand for C₁-C₂₀-alkyl, C₂-C₂₀-alkenyl, C₆C₂₀-aryl, alkylaryl having 1 to 10 carbon atoms in the alkyl radical and 6 to 20 carbon atoms in the aryl radical, for hydrogen if the latter is bonded to a carbon atom, whereby the organic radicals R³, R⁵ and R⁶ can also have inert substituents;

[0044] L is a neutral donor;

[0045] n is 0 to 3;

[0046] m is 1 for dianionic X, 2 for monoanionic X;

[0047] characterized in that an imidochromium compound having general formula V

[0048] wherein the variables have the following meaning:

[0049] R¹ stands for C₁-C₂₀-alkyl, C₂-C₂₀-alkenyl, C₆-C₂₀-aryl, alkylaryl having 1 to 10 carbon atoms in the alkyl radical and 6 to 20 carbon atoms in the aryl radical, whereby the organic radical R¹ can also have inert substituents, or SiR³ ₃;

[0050] X independent of each other, stands for fluorine, chlorine, bromine, iodine, NR⁵R⁶, NP(R⁵)₃, OR⁵, OSi(R⁵)₃, SO₃R⁵, OC(O)R⁵, β-diketonate, sulfate, dicarboxylate, dicoholates, BF₄ ⁻, PF₆ ⁻, or bulky weakly or non-coordinating anions;

[0051] R³, R⁵, R⁶ independent of each other, stand for C₁-C₂₀-alkyl, C₂-C₂₀-alkenyl, C₆C₂₀-aryl, alkylaryl having 1 to 10 carbon atoms in the alkyl radical and 6 to 20 carbon atoms in the aryl radical, for hydrogen if the latter is bonded to a carbon atom, whereby the organic radicals R³, R⁵ and R⁶ can also have inert substituents;

[0052] m is 1 for dianionic X, 2 for monoanionic X;

[0053] is reached with chlorine.

[0054] A process for the production of an imidochromium compound having the general formula III,

[0055] was likewise found, wherein the variables have the following meaning:

[0056] R² stands for R³C═NR⁴, R³C═O, R³C═O(OR⁴), R³C═S, (R³)₂P═O, (OR³)₂P═O, SO₂R³, R³R⁴C═N, NR³R⁴ or BR³R⁴;

[0057] X independent of each other, stands for fluorine, chlorine, bromine, iodine, NR⁵R⁶, NP(R⁵)₃, OR⁵, OSi(R⁵)₃, SO₃R⁵, OC(O)R⁵, β-diketonate, sulfate, dicarboxylate, dicoholates, BF₄ ⁻, PF₆ ⁻, or bulky weakly or non-coordinating anions;

[0058] R³-R⁶ independent of each other, stand for C₁-C₂₀-alkyl, C₂-C₂₀-alkenyl, C₆C₂₀-aryl, alkylaryl having 1 to 10 carbon atoms in the alkyl radical and 6 to 20 carbon atoms in the aryl radical, for hydrogen if the latter is bonded to a carbon atom, whereby the organic radicals R³and R⁶ can also have inert substituents;

[0059] L is a neutral donor;

[0060] n is 0 to 3;

[0061] m is 1 for dianionic X, 2 for monoanionic X;

[0062] characterized in that a dioxochromium compound is reacted with an N-sulfonyl compound R²—N═S═O in the process of chlorine or sulfurylchloride.

[0063] A process for the production of an imidochromium compound having the general formula VI,

[0064] was likewise found, wherein the variables have the following meaning:

[0065] R² stands for R³C═NR⁴, R³C═O, R³C═O(OR⁴), R³C═S, (R³)₂P═O, (OR³)₂P═O, SO₂R³, R³R⁴C═N, NR³R⁴ or BR³R⁴;

[0066] Z independent of each other, stands for C₁—C₂₀—alkyl, C₂—C₂₀—alkenyl, C₆—C₂₀—aryl, alkylaryl having 1 to 10 carbon atoms in the alkyl radical and 6 and 20 carbon atoms in the aryl radical, for fluorine, chlorine, bromine, iodine, NR⁵R⁶, NP(R^(5+L)) ₃, OR⁵, OSi(R⁵)₃, OC(O)R³, β-diketonate, sulfate, dicarboxylates, dialcoholates, BF₄ ⁻, PF₆ ⁻, or bulky weakly or non-coordinating anoins;

[0067] R³—R⁶ independent of each other, stand for C₁—C₂₀—alkyl, C₂—C₂₀—alkenyl, C₆—C₂₀—aryl, alkylaryl having 1 to 10 carbon atoms in the alkyl radical and 6 to 20 carbon atoms in the aryl radical, for hydrogen if the latter is bonded to a carbon atom, whereby the organic radicals R³ to R⁶ can also have inert substituents;

[0068] P is 1 for dianionic X, 2 for monoanionic Z;

[0069] characterized in that a dioxochromium compound is reacted with an N-sulfinyl compound R²—NSO.

[0070] Furthermore, a process was found for the polymerization of olefins at temperatures within the range from 0° C. to.300° C. [32° F. to 572° F] and at pressures ranging from 1 bar to 4000 bar, characterized in that the polymerization is carried out in the presence of a catalyst system according to the invention.

[0071] The process for the production of the chromium complexes can make use of a wide awmy of dioxochromium compounds as the starting materials. The important aspect is the presence of the, two oxo groups. Other ligands in the chromium starting compound are, among others the monoanionic and dianionic ligands cited for X and Z. Examples of monoanionic ligands are halogens such as, for.instance, fluorine, chlorine, bromine and iodine, amides such as, for instance, dimethylamide,. diethylamide and pyrrolidine, alcoholates such as, for example, methanolate, ethanolate, isopropanolate, butanolate, phenolate and biphenolate, carboxylates such as, for instance, acetate and trifluoroacetate, β-dibetonates such as, for example, acetylacetonate, dibenzoylmethanate, 1,1,1-tifluoro-pentane dionate and 1,1,1,5,5,5,-hexafluoropentane dionate, sulfonates such as for instance, toluene sulfonate and trifluoromethane sulfonate, C₁-C₂₀-alkyl, especially C₁-C₂₀-alkylsilyls such as, for example, methylene trimethylsilyl, bis-trimethylsilylmethyl, C₆-C₂₀-aryl such as, for instance, mesityl or wealdy or non-coordinating anions. Examples of dianionic ligands are sulfate and chelating dicarboxylates such as, for example, oxalate, fumurate, malonate or succinate and dialcoholates such as, for instance, glycolate. One or more monoanionic or dianionic ligands can be bonded to the dioxochromium compound (also see Compr. Coord. Chem. Vol. 3, G. Wilkinson, Pergamon Press 1987, First Edition, Chapter 35.6.1.3., page 935 and Chapter 35.7.1. through 35.7.2., pages 938 to 941). In addition, one or more neutral donors L can, be coordinated on the chromium educts. As a rule, the donor molecules have a heteroatom of the 15th or 16th group of the periodic table of elements. Preference is given to amines, for example, trimethylamine, dimethylamine, N,N-dimethylaniline or pyridine, ethers such as, for instance, tetrahydrofuran, diethylether, dibutylether, dimethoxyethane or dimethyldiethylene glycol, thioethers such as, for example, dimethylsulfide, esters such as, for instance, acetic acid methylester, acetic acid ethylrtro r formic acid ethylester, etones such as, for instance, acetone, benzophenone or acrolein, Schiff bases, a-diimines. phosphines such as, for cxanple, .imcthylphosphinin triethylphosphine or triphenylphouphine, phosphites such as, for instance, trimetiylphosphite or tiicfiylphosphitc, phophine oxides, phosphoric acid esters or- phosphoric acid amides such as, for example, hexamethylphosphoric acid tiamide or N-oxides. Thc chromium compounds used can be present in a wide array of oxidation stages, preferably from +4 to +6 and especially prefcrmd in thc oxidation stage +6. Prof.wsd dioxochromium compounds are dioxochromium dihalidem while diaxochrmnium dichloride is especially preferred.

[0072] The N-sulfinyl compounds employed arm, for example, N-rulfinylamines for R¹-N═S═O, while for R²-N═S═O, they are, for example, N-sulfinylcarbamidines, N-sulfinyl-carbamides, N-sulfinylcarbumutes, N-sulfinylcarboxylamides, N-sulfinylthiocarboxylamides, N-sulfinylphosphonarnides or N-sulfinylsulfonamidcs. Thc N-sulfinyl compounds can usually be prepared without problems and, as a rule, in a high yield, from compounds containing NH2 groups and sulfinylation agents such as thionylchloride, sulfur dioxide or else by means of other N-sulfinyl compounds (Z. Chem. [Journal of Chemitry] 22, (1982), pages 235 to 245).

[0073] The ridicals R³ and R⁴ are C₁-C₂₀-alkyl, whereby the alkyl can be linear. or branched, such as for example, methyl, ethyl, n-propyl, iso-propyl, n-butyl, isobutyl, ert.-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl. ndecyl or n-dodecyl, fivemrmbered to seven-membered cycloalkyl which, in turn, can have a C₆-C₁₀-aryl group as the substituent, such as, for instance, cyclopropanc, cyclobutanc, cyclopcntanc, cyclohocxanc, cycloheptane, heptare, cyclooctane, cyclononane or cyclododecane, C₂-C₂₀-alkenyl, whereby the alkenyl can bc linear, cyclic or branched and the double bond coan be internal or terminal, such as, for instance, vinyl, 1-allyl, 2-allyl, 3-allyl, butenyl. pentenyt. hexenyl. cyclopentenyl, pentenyl, cyolobexootyl, cyclooctenyl or cyclooctadienyl, C₆-C₂₀-aryl, whereby te aryl radical can be substituted by other alkyl groups such as, for example, phenyl, napthyl, biphenyl, anthranyl, o-methylphenyl, m-mcthylphenyl, p-mothylphenyl, 2,3-dimethylphenyl, 2,4-dimethylphenyl, 2,5-dirnethylphenyl or 2,6-dimethylphenyl, 2.3.4-trimethylphenyl, phenyl, 2.3,5-trimethylphtnyl, 2,3,6-trimethylphonyl, 2,4,5-trimethylphenyl, 2,4,6-tri-methylphenyl or 3,4,5-trimethylphenyl, or arylalkyl, whereby the arylalkyl can be substituted by other alkyl groups such as, for instance, benzyl, ometfiylbenzyl. m-methylbenzyl, p-methylbenzyl, 1-ethylphenyl or 2-ethylphcnyl whereby, optionally, two radicals R³ to R⁴ can also be joined to a five-membered or six-membered ring and/or can also have inert substituents such as halogcns, for example, fluorine, chlorine or bromine. Preferred R³ and R⁴ radicals are hydrogen (if it is bonded to a carbon atom), methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, tert.-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, vinyl, allyl, benzyl, phenyl, orthizubstitutcd or para-substituted alkyl or chloro-substituted, or bromo-substituted phenyls, ortho, ortho or ortho, parudiakyl-substituted or dichlorosubstitutd, or dibromosubstituted phenyls,.btnialkyl-substituted or trichloro-substituted phenyls, fluoro-substituted phenyls, naphthyl, biphenyl and anthranyl. Especially prefeffed R³ and R⁴ radicals are mothyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, tert.-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, allyl, benzyl, phenyl, 2-chlorophenyl, 2-methylphenyl, 2,6-dimethylphenyl, 2,4-dimethylphenyl, 2,6-diisopropylphenyl, 2,6-dichlorophenyl, 2,4-dichloropheny1, 2,6-dibromophenyl, 2,4dibromophenyl, 2,4,6-trimethylphenyl, 2,4,6-nrichlorophenyl and pentatluorophcnyl.

[0074] The R¹ radical can bc cither a C-organic radical, as described above for R³ and R⁴, or else an Si-ornc radical. In h case of the Si-organic substituents SiR³ ₃, thre cain also optionally be two R³ joined to a five-memberd or six-membered ring and the three R³ radicals can be selected in&plndent of each other such as, for example, trimtylsilyl, triethylsilyl, butyldimethylsilyl, uibutylsilyl, triallylsilyl, triphenylsilyl or dimethylphenylsilyl. Examnples of Si-organic substituents are especially trialkylsilyl groups having 1 to 10 carbon atoms in the alkyl radical, particularly triamcthylsilyl groups. The proferred R¹ radical is methyl, ethyl, n-propyl, iso-propyl, n-butyl, isobutyl, tert.-baityl, n-pentyl, n-hexyl, n-heptyl, n-octyl, vinyl, allyl, benzyl, phenyl, ortho-substituted or parasubstituted alkyl or. chloro-substituted, or bromo-substituted phenyls, ortho, ortho or ortho, paradiakyl-substituted or dichlora-substituted. or dibromo-nubstituted phenyls, trialkyl-aubstituted or trichloro-substituted phenyls, fluoro-substituted phenyls, naphthyl, biphenyl and antyl. Especially prrf R¹ radicals are benzyl, phonyl, 2chlorophenyl, 2methylphenyl, 2,6-dimethylphanyl, 2,4dimethylphenyl, 2.6-dii5opropylphonyl, 2,6-dichlorophtnyl, 2,4-dichlorophenyl, 2,6 bromophanyl, 2,4-dibromophenyi, 2,4.6-trimethylphenyl, 2,4,6-trichlorophenyl, pentafluorophonyl, naphthyl and anthranyl.

[0075] R² can be an imino, isocyanide, formyl, oxo, thioxo, alkoxycarbonyl, aryloxycarbonyl, carbamoyl, phosphinoyl, dialkoxyphosphoryl or diaryloxyphosphoryl, sulfonyl, dialkylamino or diarylamino or dialkylboryl or diarylboryl group. Prefetred groups are sulfonyl and oxo, especially arylsulfonyis such zw, for instance, toluene sulfonyl, benzene sulfonyl, p-trifluoromethylbenzene sulfonyl or 2,6dilsopropylbenzene sulfonyl and atyloxo such as, for example, benzoyl, 2-mothylbenmoyl, 2,6imothylbenzoyl, 2,6-diisopropylbenzoyl and 2,4,6-trimethylbenzoyl.

[0076] Imidochromium compounds as refcrtcd to below ar=monoitnidochromiurn compounds as well as bis-irnidochromium compounds.

[0077] The reaction to prepare the imidochromium compound (A) is usually cmicd out in an inert atnosphere, for example, withnitrogen or argon as the inert gas. Reaction step (a) can be conducted at tompcures between 0° C. and 150° C. [32° F. and 302° F.], prefeably between 10° C. and 100° C. [50° F. and 212° F.]. The main solvents used are aprotic solvents such a thecrs, for instance, tetrahydrofuran, diethylether, dibutylether, l,2-dimnethoxyethane or diethylene glycol dimethylothcr, alcans such as, for example, pentane, n-haxane, iso-hexa ne, tl-heptane, ooctane, cyclohexane or Decalin, aromatic compounds such as, for instanice, benzene, toluene or xylene, or chlorohydrocarbons such as methylene chlde, hlorofon, tetrachlorometliane or dichloroethane. It is also possible to employ solvent mixtures. Preference is given to alkanris and/or chlorohydrcoarbons while n-octane and/or tatrachloromethane ame especially preferred.

[0078] In Ffis context, the reaction productlfom step (a) can be subjected to tho rtond reaction sitp cithdr with or without intermeita purification or isolaion. The two reaction steps can also be performed simultancouDly in one stage. Preferably, the irnidochrmium complex with R¹ is isolated from reaction step (a) before stop (b). For imidochorium complexes with R², step (b) is optional. Therefore, the R² imidocbromium compiex can also be mixed with the activator directly, without being contacted with chlorine or sulfurylchloride, and then employed in the polymerization. Tbe. reaction products from (a) with R², however, can also be contmted with chlorine or sulfrrylohloride and only then be mixed with the activator compound. For R², steps (a) and (b) are preferably carde out simultaneously as a one-pot reaction.

[0079] The ratio of the dioxochromium compound to the N-sulfinyl compound lies between 1:1 and 1:10, preferably between 1:1 and 1:3 and especially preferred between 1:1 and 1:2.5.

[0080] Reaction step (b) can be carried out analogously to the instructions given by 0. Wilkinson et al. in J. Chem. Soc. Dalt. Trans. 1991, pages 20.51 to 2061 using the reaction product uct according to (a) instead of bis(tert.-butylimido)chromium dichloride. Sulfrrylchloride can be additionally used as the chlorine carri reagent for R². The sulfrrylchloride can be used in an excess to the compound formed from step (a). The ratio of sulfurylchloridr to the dioxochromium compound employed can be between 1:1 and 100:1, preferably between 1:1 and 10:1, and especially preferred between 1:1 and 3:1. The reaction is preferably erably carried out in tetrachloromethane. The reaction temperatim here can lie between 0° C. and 100° C. [32° F. and 212° F.], prerubly between 10° C. and 60° C. [50° F. and 140° F.] and eovially prrfcd brtwcn 20° C. and 60° C. [68° F. and 140° F.].

[0081] Special preference is given to catalyst oystems in which imidochromium compounds having the general formula I

[0082] are used, wherein the variables have the followitig meaning:

[0083] X independent of each other, stands for fluorine, chlorine, bromine, iodine, NR⁵R⁶, NP(R⁵)₃, OR⁵, OSi(R⁵)₃, SO₃R⁵, OC(O)R⁵, β-diketonate, sulfate, dicarboxylate, dicoholates, BF₄ ⁻, PF₆ ⁻, or bulky weakly or non-coordinating anions;

[0084] R¹ stands for C₁-C₂₀-alkyl, C₂-C₂₀-alkenyl, C₆-C₂₀-aryl, alkylaryl having 1 to 10 carbon atoms in the alkyl radical and 6 to 20 carbon atoms in the aryl radical, whereby the organic radical R¹ can also have inert substituents, or SiR³ ₃;

[0085] R³, R⁵, R⁶ independent of each other, stand for C₁-C₂₀-alkyl, C₂-C₂₀-alkenyl, C₆C₂₀-aryl, alkylaryl having 1 to 10 carbon atoms in the alkyl radical and 6 to 20 carbon atoms in the aryl radical, for hydrogen if the latter is bonded to a carbon atom, whereby the organic radicals R³, R⁵ and R⁶ can also have inert substituents;

[0086] L is a neutral donor;

[0087] n is 0 to 3;

[0088] m is 1 for dianionic X, 2 for monoanionic X;

[0089] R¹ and its preferred emboditnents have already been described above. The description of the radicals R³, R⁵ and R⁶ is the same as for R³ and R⁴ elaborated upon above.

[0090] The substiments X result from the selection of the appropriate chromium starting compounds that am used for the synthesis of the chromium cornplexes. Exanples of substituents X are, in particular, halogens such as fluorine, chloride, bromine or iodine, and among these especially chlorine. As additional ligands X, mention should be made of just a few examples, although this is by no means an exhaustive list, namely, BF₄ ⁻, PP₆ ⁻, as well as wealdy or non-coordinating anions (see, for instance, S. Strauss in Chem. Rev. 1993, 93,pages 927 to942) and also B(C₆F₅)₄ ⁻.

[0091] Amides, alcoholates, sulfonates, carboxylates and Pfdiketonates are especially well-suited. By varying the radicals R⁵ and R⁶, it is possible, for example, to fine-tune the physical properties, such as the solubility. Preference is given to C₁-C₁₀-alkyl such as methyl, ethyl, n-propyl, n-butyl, tert.-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl as well as vinyl, allyl, benzyl and phenyl as the radicals R⁵ and R⁶. The use of some of thPo substituted tituted ligands X is very much preferred since they can obtained from starting materials that are cheap -and readily availablc. For instance, a particularly prfctred embodiment is one wherw X stands for dimethylamide, methanolate, ethanolatw. isopropanolate, phenolate, naphtholatc, triflate, p-toluene sulfonate, acetate or acetylacetonate. Dianionic ligands of the type described in greater detail above can also be employed. It is particularly preferred if X stands for chlorine and m equals 2. Designating the ligands X as anions docs not sp5cify the type of bond to the transition m M. For example, if X is a non-coordinating or weakly coordinating anion, then the interaction between the metal M and the ligand X is more of an electrostatic nature. In contrast, in cases where, for instance. X stands for alkyl, the bond is covalenl The various types of bonds arc known to the person skilled in the art.

[0092] The donor L has also been described above, whereby n corresponds to the number of neutral donor molecules.

[0093] The imidoc rolum compound I can be monomeric or dimeric, or else polymeric. If it il dimeiic or polymeric, then one or more lirands on the chromium—this can be X, L or else the imido group—can bridge two chromium centers.

[0094] Preferred imidochronium complexes having fnula I or III are: methylimidochromium trichloride, ethylimidochromium trichloride, n-propylimidochromium trichloride, iso-propylimidochromium trichloride, n-butylimidochromium trichloride, iso-butylimidochromium trichloride, tert.-butylimidochromium trichloride, n-pentyllimidochromium trichloride, n-hexylimidochromium trichloride, n-heptylimidochromium trichloride, n-octylimidochromium trichloride, allylimidochromium trichloride, benzylimidochromium trichloride, phenylimidochromium trichloride, anthranylimidochromium trichloride, 2-chlorophenylimidochromium trichloride, 2-methylphenylimidochromium trichloride, 2,6-dimethylphenylimidochromium trichloride, 2,4-dimethylphenylimidochromium trichloride, 2,6-diisopropylphenylimidochromium trichloride, 2,6-dibromophenylimidochromium trichloride, 2,4-dichlorophenylimidochromium trichloride, 2,6-dibromophenylimidochromium trichloride, 2,4-dibromophenylimidochromium trichloride, 2,4,6-trimethylphenylimidochromium trichloride, 2,4,6-trichlorophenylimidochromium trichloride, pentafluorophenylimidochromium trichloride, trifluoromethylsulfonylimidochromium trichloride, toluene sulfonylimidochromium trichloride, phenylsulfonylimidochromium trichloride, p-trifluoromethylphenylsulfonylimidochromium trichloride or 2,6-diisopropylphenylsulfonylimidochromium trichloride, formylimidochromium trichloride, acylimidochromium trichloride, benzoylimidochromium trichloride, naphtthoylimidochromium trichloride, anthranoylimidochromium trichloride, 2-cyclobenzoylimidochromium trichloride, 2-chlorobenzoylimidochromium trichloride, 2methylbenzoylimidochromium trichloride, 2,6-dimethylbenzoylimidochromium trichloride, 2,4-dimethylbenzoylimidochromium trichloride, 2,6-diisoprpylbenzoylimidochromium trichloride, 2,6-dichlorobenzoylimidochromium trichloride, 2,4-dichlorobenzoylimidochromium trichloride, 2,4,6-trimethylbenzoylimidochromium trichloride, 2,4,6-trichlorobenzoylimidochromium trichloride or pentafluorobenzoylimidochromium trichloride.

[0095] The catalyst systems according to the invention also contain an actiator, component (B), which is put in contact with the chromdum complex. Examples of activator compounds are those of the alumoxane type (or aluminoxane), especially methyl alumoxant MAO. Alumoxanes are produced, for example, by means of tho controlled addition of water or aqueous substances to alkyl aluminum compounds, especially ethyl aluminum (for example, U.S. Pat. No. 4,404,344). Alumoxanc preparations that am suitable as cocatalysts are commercially available. It is assumed that hi. is a mixture of cyclic and linear compounds. The cyclic alumoxanes can be encompassed by the formula (R⁷AlO). and the linear aluminoxanes by the formula R⁷(R⁷AlO)₅AlR⁷ ₂, wherein 8 indicates the degree of oligomerization and it is a number ranging from about 1 to 50. Advantageous alumoxsants contain cvisrtially alumoxane oligomers having a degree of oligomerization of about 2 to 30 and R⁷ is preferably an C₁-C6-alkyl and especially prefcrably methyl, ethyl, butyl or isobutyl.

[0096] In addition to the alumoxanes, possible activator components are those of the type used in the socalled cationic activation of metallocene complexes. Such activator complexes are known, for example, from EP-B 0,468,537 and from EP-B-0,427,697. In particular, boranes, boroxines or boratesi. such as, for inste, trialkyl boran, triaryl borane, trimethyl boroxine, dimethyl anilinium tetraaryl borate, trityltetraaryl borate, dimethyl anilimum boratabenzenes or tityl boratabenzenes (see WO-A 97/36937) can be employed as such activator compounds (B). Special preference is given to the use of boranes or borates that have at least two perfluorinated aryl radicals.

[0097] Activator compounds having strong oxidizing properties can also be used such as, for instwtce, silver brates, cspecially ailvcr ttr,ispentafluorophcnyl borate or fcrrcenium borates. especially feffocenium tetrakispentafluorophenyl borate or ferrocenium tetraphenyl borate.

[0098] Compounds such as alumium alkyls. especially trimeihyl aluminum, triethyl aluminum, ttiisobutyl aluminum, ttibutyl alwminun, dimcthyl aluminum chloride, dimethyl aluminum fluoride, methyl aluminum dichloride, methyl aluminum sesquichloride, diethyl aluminum chloride or aluminum trifluoride can likewise be employed as activator com- ponent. The hydrolysis products of aluminum alkyls with alcohols can also be used (rce, for instance, WO-A 95/10546).

[0099] Furthermore alkyl corpounds of lithium, magnesium or zinc such as, for example, methyl magnesium chloride, methyl magnesium bromide, ethyl magnesium chloride, ethyl magnesium bromide, butyl magnesium chloride, phenyl manesium chloride, dimethyl magnesilim, diethyl magnesium, dibutyl. magnesium, methyl lithium, ethyl lithium, methyl zinc chloride, dimethyl zinc or diethyl zinc can be used as aativator compounds.

[0100] Especially preferred catalyst systems are those in which the activator compound (B) is selected from the following group: aluminoxane, trimethyl aluminum, triethyl aluminum, triisobutyl alumitium, dimethyl aluminum chloride, diethyl aluminum chloride, methyl aluminum dichloride, ethyl aluminum chloride, methyl aluminum sesquichloride, dimethylanilinium tatrakispantafluorophenyl borate, trityltetralspentafluorophenyl borate or trispentailuorophenyl borane.

[0101] Sometmes, it is desirable to mike use of a combinadon of several activators. This is a known procedure, for example, with mutaUocener in which boranes, booxines (WO-A 93/16116) and borates are often used in combination with an aluminum alkyl. Generally speaking, a combinatuon of various activator components with the chromium complexes acconlig to the invntion is likewise possible.

[0102] The amount of activator compounds to be used depends on the type of activator. Generally speaking, the molar ratio of chromium -complex (A) to activator compound (B) can range from 1:0.1 to1:10,000, preferably from 1:1 to 1:2000. The molar ratio of chromium complex (A) to dimethylcimliniuw tttrakiipcntafluorophenyl borat, tritylterlaispentafluoromethyl borate or trispenxtafluorophenyl borane preferably lies between 1:1 and 1:20, and especially preferred between 1:1 and 1:10, with respect to methyl aluminoxane, preferably betwmn 1:1 and 1:2000 and especially preferred between 1:10 and 1:1000. Since many of the activators such as, for instance, aluminum alkyle are concurrently employed to remove catalyst poisons (so-called scavengers), the quantity employed also depends on the purity of the other substances used. The person skilled in the anr, however, can determine the optimal amount by means of simple experimentation.

[0103] The niimre with the activator compound can be carried out in a wide arry of aprotic solvents, preformc being given to alkancs such as pcntane, hexane, heptane and octane, or to aromatic compounds such as benzene. toluene and xylene, whereby pentare, hexane, heptane and toluene are particularly preferred. Solvent mixtures, especially of alkanes with aromatic compounds, are also advantageous for purposes of adjusting to the solubilities of the catalyst system.

[0104] The mixing with the activator compound takes place at temperature between −50° C. and 150° C. [−58° F. and 302° F.], preferably between 10° C. and 50° C. [50° F. and 122° F.], especially preferred between 15° C. and 30° C. [59° F. and 86° F.].

[0105] For the polyrization, one or more of the catalyst systems according to the invention can be used simultaneously. As a result, for example, bimodal products.con be obtained. A wider product spectrum can also be achieved by using the imidochromium compounds in combination with another polymerization-active catalyst (C). In this context, at least one of the catalyst systems according to the invention is used in the presence of at least one catalyst (C) commonly employed for the polymerization of olefins. Here, preference is given to the use of Ziegler-Natta catalysts on the basis of titanium, classic Phillips catalysts on the basis of chromium oxides, metallocenes, the socalled constrained geometry complexes (see, for instance, EP-A 0,416,815 or EP-A 0,420,436), nickel and palladium bis-imine systems (for their preparation, see WO-A 98/03559), iron and cobalt pyridine-bis-Imine compounds (for their preparation, see WO-A 98127124) or chromium pyrrol compounds (see, for exampla, EP-A 0,608,447) as thO catalysts (C). Thus, by meons of such combinations. for example, bimodal products can be produced or cofnonomers can be generated in s1iu. In this context, depending on the selection of the catalyst, it is advantageous to employ one or more activators The polymerization catalysts (C) can likewise be on a support and they can be contacted simultaneously or in any desired order with the catalyst system according to the invention or with its components. A practivadon of the catalyst (C) with an activator compound (B) is likewise possible.

[0106] The description and the preferred cmbodimonts of R¹ to R⁶ and for X in the imidochromium compounds II and III as well as in the processes for the production of the chromium complexes I, III. IV and VI, the former employing the imidochromium compound V, are all the same as elaborated upon above. The reaction conditions have largely been described above as well.

[0107] Z and its preferred embodiments stand for the same described above for X and additionally also for alkyls or aryls, cspccially preferrmd for methylene trimethylsilyl, benzyl or mesityl.

[0108] The processes for the production of tho chromium complexes III and V arn fundamentally carred out under the same conditions, as a result of which the reaction parameters will be described together below.

[0109] An essential reaction step is the contacting of the N-sulfinyl compound with the corresponding dioxochrotium compound. The dioxochromium compounds have likewise been described above. Here as well, the prefrd dioxochromium compound is dioxochromium dichloride. The N-sulfinyl compounds have likewise been described above. The preferred embodiments result fiom, the preferred embodiments of the radicals R¹ or R² of the imido grup of the chromium complex being formed (see above). The reaction step has already been described above for the reaction step (a). This can be followed by a regular purification step, for instance, recrystallization or filtration.

[0110] The process according to the invention for the polymerization of olefins can be combined with all of the technically known polymerization methods at temperatures within the range from 0° C. to 300° C. [32° F. to 572° F.] and at pressures ranging from 1 bar to 4000 bar. Themfore, the advantageous pressure and temperature ranges at which to carry out the process depend to a great extent on the polymerization method. Thus, the catalyst systems used according to the invention can be employed in all of the known polymerization processes such as, for example, a high-pressure polymnrizaion process in tubular-flow reactors orf autoclaves, in suspensionpolymeriion. processes, in solution-polymerization processes or in gas-phase polymerization. In the case of the high-pressure polymerization process, which is normally carried out at pressures between 1000 and 4000 bar, especially between 2000 and 3500 bar, high polymerization temperatures are usually set as well. Advantagcous temperature ranges for these high-pressure polymerization processes lie between 200° C. and 300° C. [392° F. and 572° F.], especially between 220° C. and 270° C. [428° F. and 518° F.]. When it comes to the low-pressure polymerization process, the selected temperature is usually at least a few degrees below the softening point. of the.e.polymer. The polyrizaion temperature can be between 0° C. and 180° C. [32° F. and 356° F.]. In particular, temperature between 50° C. and 180° C. [122° F. and 356° F.], preferably between 70° C. and 120° C. [158° F. and 248° F.], are set in these polymerization processes. Among the polyinerimation methods mentioned, preerenceis given according to the invention to gas-phase polymLrizution, especially in gew-phase fluidized-bed reactors, as well as to suspension polymerization, particularly in loop-type reactors and stirred-tank actors as well as to solution polymerization. Gas-phase polymceization can also be prformied in the so-called condensed, supercondensed or supercritical mode of operation. Different or else the same polymerization methods can optionally also be connected with each other in series so as to create a polymerization cascade. Moreover, in order to regulate the polymer properties, an additive such as, for instance, hydrogen, can also be used in the polymerization processes.

[0111] Using the process according to the invention, variour olcilnically unsatuated compounds can be polymerized, which also includes copolymerization. In contrast to a few known iron and cobalt complexes, the transition-metal complexes used according to the invention exhibit good polymerization activity, even with higher a-olefins, so that special mention needs to be made of their suitability for copolymerization. Aside from ethylene and a-olefins having 3 to 12 carbon atoms, examples of olefims arc also internal olofins and non-cougated. and conjugated. dienes such as butadiene, 1,5-hexadiene oi 1.6-heptadiene, cyclic olefii such as cyclobutene, cyclopentene or norbomene and polar monomers such as attylic acid ester, acrolein. acrylonitrile. vinylether, allylether and vinylacetate. Vinyl-aromatic compounds such as styrene can also be polymerized by means of the process according to the invention. Preferably, at Ioast one olofin selected from the group consisting of ethene, propene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, cyclopentene and norbornene is polymerized. A preferred embodiment of the process according to the invention is characterized in that mixtures of ethylene with C₃C₈-α-olefins are used as the monomers.

[0112] In this context, the chromium complex can be brought into contact with the activator compound or compounds either before or after contacting with the olefins to be polymerized. Another possibility is preactivation with one or more activator compounds prior to mixing with the olefin and the fewer addition of the same or different activator compounds after this mixture has been contacted with the olefin. As a rule, preactivation is conducted at temperatures between 10° C. and 100° C. [50° F. and 212° F.], preferably between 20° C. and 80° C. [68° F. and 176° F.].

[0113] Furthermore, more than one of the catalyst systems according to the invention can be siimultamously brought into contact with the olefin to be polymtzeid Ibis has the advantage that a wide range of polymers can be thus created. In this nanner, bimodal produots, for example, can be produced.

[0114] The catalyst systems according to the invention can optionally also be immobilizmd on an organic or inorganic support and then be used in the polymerization in this supported forn. This is a coimnmon method employed to avoid reactor deposits and to regulate the polymer morphology. Preferable support materials are slica gel, magnesium chloride, aluminum oxide, mesoporous materials, alumosiilicates and organic polymers such as polyethylene, polypropylene or polystyrene and especially silica gel or magnrsium chloride.

[0115] One or more of the catalyst systems, according to the invention can be immobilized on a support. The components of the catalyst system can be put into contact with the support in varying orders or all at the same time. This is usually done in an inert solvent that can be filtered off or ovaporatrd after the immobilization procedure. The use of tew still moist, supported catalyst is also possible. For instance, the support can be frt mnixed with the activator compound or compounds or clso the support can first be contacted with the polymerization catalyst. Pre-activation of the catalyst with one or more activatmr compounds prior to the mixing with the support is also possible. The amount of chromium complex (A) in mnolces per gra of support material can vary widely, for example, fom 0.001 to 1 mmole/g. The preferred quantity of chromium complex (A) per gram of support zaterial lies between 0.001 and 0.5 mmole/g, especially preferably between 0.005 and 0.1 mmolelg. In one possible embodiment. the chromium complex (A) can also be produced in the presence of the support material. Another type of immobilization is the prepolymerization of the catalyst system with or without a prior supporting step.

[0116] Polymers of olefins can be produced by means of the process according to thc invention. The tenn polymenization as employed here to describe the invention comprises both polymeration and oligomerization, that is to say, oligomers and polymers having molecular weights within the range from about 56 to 4,000,000 can be produced by means of this process.

[0117] In view of thcir good mechanical properties. the polymers produced with the catalyst system ao g tonthe invention are pacularly suitable for the manufactur of filus, fibers and molded articles.

[0118] The catalysts according to the invention display moderate levels of productivity.

[0119] The comparative examples for the bis-imidochromium compounds descraibed in EP-A 0,641,804 show that the monoirido compound according to the invention. (C₆F₅N)CrCl₃. yielded higher levels of activity. In comparison to the bis-iinido compounds, the norbomene polymerization did not yield any metathesis products.

[0120] The new process fbio the production of bis-imidochromium compounds is a one-pot synthesis. In this manner, up to two synthesis steps can be dispensed with in the preparation of bis(arylimido)chromium complexes.

[0121] N-sulfnylamincs havc been enployod by S. Chenini and M. Pizzotti (Inorg. Chim. Acta [Inorganic chemical arrhives] 42, (1980), 65) for the synthesis of molybdenum imido compounds. It was assumed that the released SO₂ would reduce the chromium gpecies whcn the reduction-prone chromium(VI)dioxo-compounds are used. Surprisingly, however, this was not observed,

[0122] The examples that follow serve to illustrate the invention.

[0123] Unless otherwisc indicatxd all of the work was performed in the absence of air and moisture. Toluene was dried and distilled off over a molecular sieve column or potassium-benzophenone. Triethyl aluminum (2 M in hoptano) and MAO (medtyl aluminoxane 30% in toluent) wav obtained from the Witco GmbH and Albemarle companies.

Analytical Methods

[0124] The elementary analyses were carried out using a Heraeus CNN-Rapid unit.

[0125] The IR spectra were obtained with a Nicolet 510M as a Nujol tdturation between KBr plates.

[0126] The η value wsto determnad with nn automatic Ubbelohde viscosimter (Lauda PVS 1) with Decalin as the solvent at 130° C. [266° F.] (ISO 1628 at 130° C. [266° F.], 0.001 g/mL of Decalin).

[0127] E1 mass spectra wele obtained with a Vatian MAT CH7 unit.

[0128] The melting points were determined by means of a Melting Point B-540 device manufactured by the Buechi company.

[0129] The NMR spectra were obtained with a Bruker ARX 200 unit or with a Bruker AMX 300 unit.

[0130] Koy to the abbreviations used in the following tables:

[0131] Cat. ex. Catalyst acrcording to the example

[0132] yield yield of polymer

[0133] gP of grams polymer

[0134] Tg glas transition temperature

[0135] Tm melting trmparature

[0136] h Staudinger index (viscosity)

[0137] tBu tert.-butyl

[0138] Ts para-toluene sulfone

[0139] Bz benzoyl

[0140] Tf trifluoromethane sulfone

EXAMPLE 1

[0141] Preparation of-bis((2,6-diisopropylphenyl)imido)chromim dichloride

[0142] A 0.84-molar solution of chromylehloride in CCl₄ (455 mg, 2.94 mmoles of CrO₂Cl₂) wasdiluted with 30 mL of octane and slowly mixed with 1.45 g (6.47 mmnoles) of (2,6-diisopropylphenyl)sulfinylamine.

[0143] The reaction mixture was subsequentdy heated for 12 hours under reflux, whereby, at certain times, a stream of inert gas was passed through tho rraction solution in order to expel the SO₂ that was frming. The precipitated brown-violet solid was filtered off, washed with cold pentane and dried in a high vacuum. Yield: 1.22 g (88%) of bis(diisopropylphenylimido)chromium dichloride.

[0144]¹H-NMR (C₆D₆, 200 MHz): δ=1.08 (d, 24H, 3I_(HH)=6.8 Hz, CH (CH₃ )₂), 3.86 (sept, 4H, 3I_(HH)=6.7 Hz, CH(CH₃)₂), 6.72 (s, 6H, Ph-H) ppm.

[0145]¹³C-NMR (C₆D₆, 50 MHz): δ=23.5 (CH(CH₃)₂), 30.0 (CH(CH₃)₂), 123.7 (Ph-C _((meta))), 132.3 (Ph-C _((potu))), 148.9 (Ph-C _((ortho))) ppm.

[0146] IR (Nujol): ≡2855 s, 1642 w, 1582 m, 1296 m, 1262 m, 1221 w, 1142 w, 1080 m(br), 1022 m(br), 912 w, 799 m, 754 w, 721 w, 563 m cm⁻¹.

[0147] EI-MS: m/z=175 (DipN⁺, 57%), 160 (Dip-H, 71%), 119 (C₉H₁₂ ⁺, 25%), 36 (Cl, 100%).

[0148] Dip=2,6-diisopropylphenyl

[0149] Ph=phoyl

EXAMPLE 2

[0150] Preparation of bis(tert.-butylimido)chromium dichloride

[0151] A 0.84-molar solution of chromylchidride in CCl₄ (566 mg, 3.67 mmoles of CrO₂Cl₂) was diluted with 20 mL of octane and twiid with 963 g (8.08 mmoles) of tert.-butylsulfinylamine. The reaction mixture was subsequently heated for 12 hours under refnLX, whereby, at certain times, a stmam of inert gas was paabcd through the reaction solution in order to expel the S0₂ that was frmning. The precipitated violet solid W8S filtered off, washed with cold pentane and dried in a high vacuum. Yild: 770 mg (79%) of bis(tert.-butylimido)chromium dichloride.

[0152]¹H-NMR (CDCl₃, 200 MHz); δ=1.60 (s, 18H, C (CH₃ )₃) ppm.

[0153]¹³C-NMR (CDCl₃, 50 MHz): δ=30.2 (C(CH₃)₃) ppm.

EXAMPLE 3

[0154] Preparation of bis((2,4,6,-triethylphonyl)imido)chromium dichloride

[0155] A 0.84-molar solution of chromylchlonde in CCl₄ (605 mg, 3.92 mmole; of CrO₂Cl₂) was diluted witll 20 mL of octane and slowly mixed with 1.66 g (8.63 mmoles) of mesitylsulfinylaminc. Thr, riaction niixwrm was subsequently heated for 12 hours under reflux whereby, at certain times, a stuein of inert gas was pascd through the reaction solution in order to expel the SO₂ that was forming. The precipitated red-brown solid was filterod off, washrd with cold pentane and dried in a high vacuum. In this manner. bis((2.4.6,-triethylphenyl)imido)chromium dichloride was isolated in a yield of 91%.

[0156]¹H-NMR (C₆D₆, 200 MHz): δ=1.84 (s, 6H, Mes-CH ₃)_((para))), 2.25 (s, 12H Mes-CH₃ )_((ortho))), 6.23 (s, 4H, Mes-H _((meta)))) ppm.

EXAMPLE 4

[0157] Preparsdon of bis(pentafluorophenylimido)chromium dichloride

[0158] A 0.84-molar solution of chiomylchloride in CCl₄ (3.30 8, 21.4 mmOIeS of CrO₂Cl₂) was diluted with 80 mL of tetrachloromethane and mixed with 10.79 g (47.08 mmoles) of pentafluorophanylsulfinylamine at room temperature. The reaction mixture was subsequently stirred for 4 hoaim until here was no more gas formation to be seen. During the cooling off phacs, a weak stream of inert gas was passed rough te reaction solution in order to expel the SO₂ that had famed during the reaction. The precipitated dark-red solid was filtered off, washed with cold pentane and dried in a high vacuum. Yield: 95% of bis(pentafluorophenylimido)chromium dichloride.

[0159]¹⁹F-NMR (CDCl₃, 188 MHz): δ=−144.2 (d, 4F, 3I_(FF)=15.3 Hz, Arf-F_((ortho))), −148.3 (t, 2F, 3I_(FF)=20.4 Hz, Arf-F_((para))), −155.9 (t, 4F, 3I_(FF)=20.3 Hz, Arf-F_((meta))) ppm.

[0160] IR (Nujol): ≅1632 s, 1507 s, 1263 m, 1150 m, 1121 m, 1063 s, 997 s, 864 w, 802 w, 721 w, 642 m, 561 m, 440 w cm⁻¹.

[0161] Arf=pentafluorophenyl.

EXAMPLE 5

[0162] Reaction of dioxochromiumdichloride, with N-(toluene sulfonyl)sulfinylamide

[0163] A 0.84-molar solution of chromylchloride in CCl₄ was mnixed at room temperature with 2.2 equivalents of sulfinylamide dissolved in tetrachloromethane. Subsequently, the reaction mixturo was heated under a reflux until there was no more gas formation to be seen. The resultant brown solid was filtered off, washed with pentane and dried in a high vacuum. Yield: 90%.

[0164] Only a sharp sigal was observed in the EPR ipecvum for this compound. Mean values of the elementary analysis: C 25.31 H 2.37 N 3.28 Cl 22.89 S 12.15 Cr 13.16

EXAMPLE 6

[0165] Reaction of dioxochromiumdichloride with N-(toluene sulfonyl)sulfinylamide in the presence of chlorine

[0166] A 0.84 olr rolution of chromylchloride in CCl₄ was mlxed at room temperatUw with 2.2 equivalents of N-(toluene sulfonyl)sulfinylamids dissolved in tetrachloromrcthane. A stream of chlorine gas was passed through the reaction solution for 10 minuts. Subsequently, the reaction mixwtm was heated under a reflux until the was no more gas formation to be seen. During the reaction as well, a walk stram of chlonine gas was passed ffirough. thr rcaction solution. The resultant yellow-brown solid was filtered off, washd with pentane and dtied in a high vacuum. The yield was approximately 90%.

[0167] As an altemative, instead of chline gas, 5 mL of sulfurylchloride can be added to the above-mentioned solution. After agitation for 24 hours at room temperature, the preparation proceecc analogously.

[0168] Very wide, weak signals can be observed in the ¹H-NMR speCtrlmM, which indicates a paramagnetic compound.

EXAMPLE 7 to 9

[0169] Reaction of the bis(imido)chromiura dichlonde with chlorine (analogously to G. Wilkinson et al. L in J. Chem. Soc. Dalt. Trans. 1991, pages 2051 to 2061).

[0170] These experiments were caiied out for complees having the following radicals on the irndo liguniids: tcrr.-butyl (7),2,6-diisopropylphenyl (8) and pentafluorophenyl (9).

[0171] A total of 5 g of bis(imidochromiium dichlotide was dissolved in 50 mL of methylene chloride. At room tmperature, a sftm of chlorine gs was passed thi& ugh the reaction solution for 10 minute. Subsequrntly, the mltuw was left tandmfg for one hour at room temperature, after which the voladle components were removed in a vacuum.

[0172] These reactions tnspi virtually quantitatively. Elementary analyses: (8) calculated: C 43.20 H 5.14 N 4.20 found: C 41.60 H 5.24 N 5.46 (9) calculated: C 21.23 N 4.13 found: C 21.27 N 4.25

EXAMPLE 10

[0173] Ethne polymcriztion

[0174] A total of 0.20 mmole of the chromium compound from example 5 was dissolved in 61 niL of toluene. The solution was transferred into a 250 mL glass autoclave, where it was first brought to a tomperature of 0° C. [320F.] and subsqucndy sawrated with ethene for 30 miiutes at 13 bar. Thc thfe rcar on was Btated by ag 670 mg of MAO (Cr:Al=1;50) dissolved in 40 mL of toluene. The fint polymer partieles alrcady preipitatcd fom the rmtion soluton aftcr a few minutc. After a reaction dme of 3 hours, the reaction was inttnrpted by dripping the polyrnization mixture into a mixturo of methanol and hydrochloric acid. The polymer precipitate obtained in this process was filtered off, washed with methanol and dried in a vacuum at 100° C. [212° F.]. The yield was 2.3 g of polyethylene having a melting point of 136° C. [276.8° F. ] and 19.

EXAMPLE 11

[0175] Norbomene ethene copolymerization

[0176] First of all, 0.200 mmole of the chromium compound from Example 5 was suspended in 50 mi of toluene. This solution wa then put into a 250-mL glass autoclave. Subsequently, 40 mL of a norbornene-toluene solution (318.60 mmoles of norborene) were added to this solution. The reaction mixture thus obtained was fitst brought to a temperature of 0° C. [32° F.] and subsequently saturated with othene for 30 minutes at 3 bar. Thrcn the reaction was stated by adding 1.34 g of MAO (Cr:Al=1:50) dissolved in 20 mL of toluene. After a reaction time of 1.5 hours, tho reaction was interrupted by dripping the podymerization mixtuir into a mixturc of methanol and hydrochloric acid. The polymer precipitate obtained in this process was filtered off, washed with methanol and dried in a vacuum at 70° C. [158° F.]. The yield was 28 g of a polymer having a T_(g) of 128° C. [262,4° F.].

EXAMPLE 12

[0177] Hexene polymeization

[0178] First of alL 0.106 nmnole of the chromium compound from Example 5 was dissolved in 10 mnL of toluene. Then 2.64 mL of 1-hexene (21.24 mmoles) were added to this solution. Iehe reaction mixture thus obtained was brought to a tempete of 25° C. [77° F.] and the polymerization was started by adding 300 mg of MAO (Cr:Al 1:50) dissolved in 3 mL of toluene. After a reaction time of 3 days, the polymerization was interrupted by driping the polymiizadon milxmre into a mixmr of methanol and hydrochloric acid. Ibc yield was an oily, tcky precipitate that could not be filbred. Therefore, the :etanol.was distllled off once again and the resultant residue was picked up in 50 mL of cyclohexane. Then 10 mL of water wcr added to this solution in aider to farm a lower layer for purposes of washing the obtained polymer free of chromium, Afterwards, the aqueous phase was separated out. The solvent was distilled out of the organic phase in a vacuum and the polymer residue obtained was dried in a vacuum. The yield was 3% polyhexene.

EXAMPLES 13 to 16

[0179] Norbornene polymerization

[0180] A) Activation of the catalyst with a commercially available MAO toluene solution:

[0181] First of all, 0.106 mmole of the chromium compound fmm Example 5 was mixed with 2 g of norbratcne in 10 mL of toluene. The reaction mixture thus obtained was brought to a temperature of 25° C. [77° F.] and the reaction was started by adding 3 mL of 1.53 M methylalumnoxane solution (in toluono). After a reaction time of one hour, the reaction was interrupted by dripping the polymerization mixture into n mixtur of methanol and hydrochloric acid. The resulting polymer precipitate was filtered off, washed with methanol and dried in a vacuum.

[0182] B) Activation of the catalyst with solid MAO that was picked up again in toluene; First of all, 0.106 mmolc of the chromium compound from Example 5 was mixed with 2 g of norbornene dissolved in 10 mL of toluene. The reaction mixture thus obtained was brought to a temperature of 25° C. [77° F.] and the reaction was started by adding 300 mg of MAO dissolved in 3 mL of toluene. After a reaction time of one hour, the traction was interupted by dripping the polymerization mixture into a milturr of methanol and hydrochloric acid. The resulting polymer precipitate was faltered off, washed with methanol and dried in a vacuum.

[0183] The results of the polymerizations can be sen in Table 1.

COMPARATIVE EXAMPLES 17 and 18

[0184] Norbornene polymerization

[0185] The experiments were conducted as described above for the norbomene polymerization B). The chromium compound from Example 4 wa3 used in Example 17, while the chromium compound fiom Example 2 was employed in Example 18.

[0186] The results of the polymcrizations can bc found in Table 1. TABLE 1 Results of the norhornene polymerization. Example Metathesis^(a)) Yield 13 (A) no 82% 14 (B) no 95% 15 (A) no  5% 16 (B) no 53% 17 (B) yes 89% 18 (B) yes  5%

EXAMPLES 19 to 24 Ethene polymerization

[0187] A total of 0.05 mmole of the cmium compound indiated in Table 2 was dissolved in 20 mL of toluene. The solution was tnmsferred into a 250-mL glass autoclave, where it was first brought to a temperature of 60° C. [140° F.] and subsequenty saturated with ethlne for 30 minutes at 3 bar. Then the rection was rtarted by adding 12.5 mmoles of MAO (Cr:Al=1:250) dissolved in 20 mL of toluene. The first polymer ptiles aizady precipitated from the reaction solution af a few minutes. After a reaction time of 30 minutes 60° C. [140° F.] under a conatant ethylene pressure of 3 bar, the reaction was interrupted by dripping the polymerization mixture into 400 maL of a mixture of methanol and concentrated hydrochloric acid (10:1). The polymer preipitatc obtaind in this process was filtered off, washcd with methanol and dried in a vacuum at 100° C. [212° F.].

[0188] Example 24 is presented for comparison purposes. TABLE 2 Results of the ethylene polymerization. Quantity Yield Activity Example Catalyst [mg] [mg] [gPE/mmole · bar · h] 19 [Cr(N^(t)Bu)Cl₃] 11.5 287 3.8 20 [Cr(N₆F₅)Cl₃] 17 1001 13.4 21 [Cr(NT₈)Cl₃] 16.4 383 5.1 22 [Cr(NBz)Cl₅] 13.8 224 3 23 [Cr(NTf)Cl₃] 15.3 285 3.8 24 [Cr(NC₆F₅)₂Cl₂] 24.3 428 5.7

EXAMPLES 25 to 27

[0189] Ethane polymerization

[0190] A total of 400 mL of toluene was placd into a one-liter autoclave at a temperature of 70° C. [158° F.], after which the amount of catalyst indicated in Table 3 was suspended in 2.5 mL of a 30%-solution of MAO (12 mmoles) and placed into the reactor after 10 minutes. The polymerization was stare by pressurization with ethylene at 40 bar. After a polymerization time of one hour with ethylene at 40 bar and 70° C. [158° F.], the reaction was interrupted by relieving the pressure and the polymer was processed in the manr described above. TABLE 3 Results of the ethylene polymerization. Activity η Catalyst Quantity Hexene Yield [gP/mmole · [dL/ Example (example) [mmole] [mL] [g] bar · h] g] 25 5 0.056 — 12 5.4 6.3 26 5 0.056 40 7 3.1 5.69 27 8 0.06 — 3 1.2 15.1

EXAMPLE 28

[0191] Ethane polymerization

[0192] The polymerizaeion was conducted as described above for Examples 25 to 27. The chromium complex from Example 9 was used. 2 mL of triethyl aluminum (4 mmoles) were used as the co-catalyst.

[0193] A total of 14.5 g of polyethylene having an η value of 7.8 dL/g was obtained. The activity was 3 gP/mmole·bar·h. 

1-14. (Cancelled).
 15. An imidochromium compound having the general formula II,

wherein: R² is R³C═NR⁴, R³C═O, R³C═O(OR⁴), R³C═S, (R³)₂P═O, (OR³)₂P═O, SO₂R³, R³R⁴C═N, NR³R⁴ or BR³R⁴; X independent of each other, is fluorine, chlorine, bromine, iodine, NR⁵R⁶, NP(R⁵)₃, OR⁵, OSi(R⁵ )₃, SO₃R⁵, OC(O)R⁵, β-diketonate, sulfate, dicarboxylate, dialcoholate, BF₄ ⁻, PF₆ ⁻, or bulky weakly or non-coordinating anions; R³-R⁶ independent of each other, are C₁-C₂₀-alkyl, C₂-C₂₀-alkenyl, C₆-C₂₀-aryl, alkylaryl having 1 to 10 carbon atoms in the alkyl radical and 6 to 20 carbon atoms in the aryl radical, hydrogen if the latter is bonded to a carbon atom, whereby the organic radicals R³ and R⁴ optionally have inert substituents; m is 1 for dianionic x, 2 for monoanionic x.
 16. An imidochromium compound having the general formula III,

wherein R² is R³C═NR⁴, R³C═O, R³C═O(OR⁴), R³C═S, (R³)₂P═O, (OR³)₂P═O, SO₂R³, R³R⁴ or BR³R⁴; X independent of each other, are fluorine, chlorine, bromine, iodine, NR⁵R⁶, NP(R⁵)₃, OR₅, OSi(R⁵)₃, SO₃R⁵, OC(O)R⁵, β-diketonate, sulfate, dicarboxylate, dialcoholate, BF₄ ⁻, PF₆ ⁻, or bulky weakly or non-coordinating anions; R³-R⁶ independent of each other, are C₁-C₂₀-alkyl, C₂-C₂₀-alkenyl, C₆-C₂₀-aryl, alkylaryl having 1 to 10 carbon atoms in the alkyl radical and 6 to 20 carbon atom in the aryl radical, hydrogen if the latter is bonded to a carbon atom, whereby the organic radicals R³ to R⁶ can also have inert substituents; L is a neutral donor; n is0to3; m is 1 for dianionic X, 2 for monoanionic X.
 17. A process for the production of an imidochromium compound having the general formula IV,

wherein R¹ is C₁-C₂₀-alkyl, C₂-C₂₀-alkenyl, C₆-C₂₀-aryl, alkylaryl having 1 to 10 carbon atoms in the alkyl radical and 6 to 20 carbon atoms in the aryl radical, whereby the organic radical R¹ can also have inert substituents, or SiR₃ ³; Z independent of each other, are C₁-C₂₀-alkyl, C₂-C₂₀-alkenyl, C₆-C₂₀-aryl, alkylaryl having 1 to 10 carbon atoms in the alkyl radical and 6 to 20 carbon atoms in the aryl radical, fluorine, chlorine, bromine, iodine, NR⁵R⁶, NP(R⁵)₃, OR⁵, OSi(R⁵)₃, SO₃R⁵, OC(O)R⁵, β-diketonate, sulfate, dicarboxylate, dialcoholate, BF₄ ⁻, PF₆ ⁻, or bulky weakly or non-coordinating anion; R³, R⁵ and R⁶ independent of each other, are C₁-C₂₀-alkyl, C₂-C₂₀-alkenyl, C₆-C₂₀-aryl, alkylaryl having 1 to 10 carbon atoms in the alkyl radical and 6 to 20 carbon atom in the aryl radical, hydrogen if the latter is bonded to a carbon atom, whereby the organic radicals R³, R⁵ and R⁶ can also have inert substituents; p is 1 for dianionic Z, 2 for monoanionic Z, which comprises reacting a dioxochromium compound with an N-sulfinyl compound R¹-NSO wherein R¹ is defined above.
 18. A process for the production of an imidochromium compound having the general formula I,

wherein R¹ is C₁-C₂₀-alkyl, C₂-C₂₀-alkenyl, C₆-C₂₀-aryl, alkylaryl having 1 to 10 carbon atoms in the alkyl radical and 6 to 20 carbon atoms in the aryl radical, whereby the organic radical R¹ can also have inert substituents, or SiR₃ ³; X independent of each other, are fluorine, chlorine, bromine, iodine, NR⁵R⁶, NP(R⁵)₃, OR⁵, OSi(R⁵)₃, S0₃R⁵, OC(O)R⁵, β-diketonate, sulfate, dicarboxylate, dialcoholate, BF₄ ⁻, PF₆ ⁻, or bulky weakly or non-coordinating anions; R³, R⁵ and R⁶ independent of each other, are Cl-C₂₀-alkyl, C₂-C₂₀-alkenyl, C₆-C₂₀-aryl, alkylaryl having 1 to 10 carbon atoms in the alkyl radical and 6 to 20 carbon atoms in the aryl radical, for hydrogen if the latter is bonded to a carbon atom, whereby the organic radicals R³, R⁵ and R⁶ optionally have inert substituents; L is a neutral donor; m is 1 for dianionic X, 2 for monoanionic X. n is 0 to3; which comprises reacting an imidochromium compound having the formula V

with chlorine wherein R¹, X and m are defined above.
 19. A process for the production of an imidochromium compound having the general formula III,

wherein R² is R³C═NR⁴, R³C═O, R³C═O(OR⁴), R³C═S, (R³)₂P═O, (OR³)₂P═O, SO₂R³, R³R⁴C═N, NR³R⁴ or BR³R⁴; X independent of each other, are fluorine, chlorine, bromine, iodine, NR⁵R⁶, NP(R⁵)₃, OR⁵, OSi(R⁵)₃, SO₃R⁵, OC(O)R⁵, β-diketonate, sulfate, dicarboxylate, dialcoholate, BF₄ ⁻, PF₆ ⁻, or bulky weakly or non-coordinating anion; R³-R⁶ independent of each other, are Cl-C₂₀-alkyl, C₂-C₂₀-alkenyl, C₆-C₂₀-aryl, alkylaryl having 1 to 10 carbon atoms in the alkyl radical and 6 to 20 carbon atoms in the aryl radical, hydrogen if the latter is bonded to a carbon atom, whereby the organic radicals R³ to R⁶ can also have inert substituents; L is a neutral donor; m is 1 for dianionic X, 2 for monoanionic X. n is0to3; which comprises reacting a dioxochromium compound with a N-sulfinyl compound R²-N═S═O in the presence of chlorine or sulfurylchloride.
 20. A process for the production of an imidochromium compound having the general formula VI,

wherein R² is R³C═NR⁴, R³C═O, R³C═O(OR⁴), R³C═S, (R³)₂P═O, (OR³)₂P═O, SO₂R³, R³R⁴C═N, NR³R⁴ or BR³R⁴; Z independent of each other, are Cl-C₂₀-alkyl, C₂-C₂₀-alkenyl, C₆-C₂₀-aryl, alkylaryl having 1 to 10 carbon atoms in the alkyl radical and 6 to 20 carbon atoms in the aryl radical, fluorine, chlorine, bromine, iodine, NR⁵R⁶, NP(R⁵)₃, OR⁵, OSi(R⁵)₃, SO₃R⁵, OC(O)R⁵, β-diketonate, sulfate, dicarboxylate, dialcoholate, BF₄ ⁻, PF₆ ⁻, or bulky weakly or non-coordinating anion; R³-R⁶ independent of each other, are C₁-C₂₀-alkyl, C₂-C₂₀-alkenyl, C₆-C₂₀-aryl, alkylaryl having 1 to 10 carbon atoms in the alkyl radical and 6 to 20 carbon atoms in the aryl radical, hydrogen if the latter is bonded to a carbon atom, whereby the organic radicals R³ and R⁴ can also have inert substituents; p is 1 for dianionic Z, 2 for monoanionic Z, which comprises reacting a dioxochromium compound with an N-sulfinyl compound R²-NSO. 